Analysis and acquisition of multichannel data in electrocardiology.
Explore the source record for details and available documents.
Arrhythmias, Cardiac↗
SEARCH · Search PubMed
Results for “Data Storage And Retrieval”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Pitfalls and paths to success in interdisciplinary scientific database research.
Explore the source record for details and available documents.
Biological Science Disciplines↗
Views on visualization.
The field of visualization is maturing. Many problems have been solved and new directions are sought. In order to make good choices, an understanding of the purpose and meaning of visualization is needed. In this paper, visualization is considered from multiple points of view. First, a technological viewpoint is adopted, where the value of visualization is measured based on effectiveness and efficiency. An economic model of visualization is presented and benefits and costs are established. Next, consequences and limitations of visualization are discussed (including the use of alternative methods, high initial costs, subjectiveness, and the role of interaction). Example uses of the model for the judgment of existing classes of methods are given to understand why they are or are not used in practice. However, such an economic view is too restrictive. Alternative views on visualization are presented and discussed: visualization as an art, visualization as design and, finally, visualization as a scientific discipline.
Computer Graphics↗
Design and evaluation of tiled parallel coordinate visualization of multichannel EEG data.
The field of visualization assists data interpretation in many areas, but does not manage all types of data equally well. This holds, in particular, for time-varying multichannel EEG data. No existing method can successfully visualize simultaneous information from all channels in use at all time steps. To address this problem, a new visualization method is presented based on the parallel coordinate method and making use of a tiled organization. This tiled organization employs a two-dimensional row-column representation, rather than a one-dimensional arrangement in columns as used for classical parallel coordinates. The usefulness of the new method, referred to as tiled parallel coordinates (TPC), is demonstrated by a particular type of EEG data. It can be applied to an arbitrary number of time steps, handling the maximum number of channels currently in use. An extensive user evaluation shows that, for a typical EEG assessment task, data evaluation by the TPC method is faster than by an existing clinical EEG visualization method, without loss of information. The generality of the TPC method makes it widely applicable to other time-varying multivariate data types.
Computer Graphics↗
Geometric misalignment and calibration in cone-beam tomography.
We present a new high-precision method for the geometric calibration in cone-beam computed tomography. It is based on a Fourier analysis of the projection-orbit data, recorded with a flat-panel area detector, of individual point-like objects. For circular scan trajectories the complete set of misalignment parameters which determine the deviation of the detector alignment from the ideal scan geometry are obtained from explicit analytic expressions. To derive these expressions we show how to disentangle the problems of calculating misalignment parameters and point coordinates. The calculation of the coordinates of the point objects inside the scanned volume, in units of the distance from the focal spot to the center of rotation, is then possible analytically likewise. We simulate point-projection data on a misaligned detector with various amounts of randomness added to mimic measurement uncertainties. This data is then employed in our calibration to validate the method by comparing the resulting misalignment parameters and point coordinates to the known true ones. We also present our implementation and results for the geometric calibration of micro-CT systems. The effectiveness of the corresponding misalignment correction in reducing image artifacts is exemplified by reconstructed micro-CT images.
Algorithms↗
Requirements for PACS: users' perspective.
The applications for which picture archiving and communication systems (PACS) will be used must dictate the technological requirements. Technology-driven integrated PACS have been implemented and tested in a variety of clinical environments. PACS do not generate new revenues, albeit they may affect the bottom line of health care delivery systems through increased efficiency of radiology and, perhaps more important, of the other physicians who use radiologic services. User performance expectations require that trade-offs are evaluated and compromises are made when PACS are designed using currently available technology. In this report, functional requirements for clinical PACS are discussed. These include reliability, speed, ease of use, connectivity, and upgradability. The advantages and disadvantages of specific choices are presented from a utility perspective of an end user.
Computer Communication Networks↗
A computer program designed for the analysis of data from rat caries studies.
The Keyes method for scoring dental caries in the rat animal model has been used as the basis for a computer-assisted scoring system on the Apple Macintosh personal computer that is described here. The program provides the ability to draw on diagrams of the rat molar dentition and to enter enamel lesion scores (L, E) and dentinal lesion scores (Ds, Dm, and Dx) for all aspects of the molars. The scores and drawings may be changed at any time. Total carious teeth and totals of L, E, Ds, Dm, and Dx are automatically calculated and presented upon user command. Error trapping for typographical errors is provided. In addition, the program provides automatic storage of the collected information, searching and sorting on any of the experimental parameters and on-disk help files that can be accessed from any place within the program. The capacity to obtain printed copy of any or all of the stored information is provided in the program. The program also enables the creation of external data files containing totals for carious teeth, in addition to L, E, Ds, Dm, and Dx totals for each animal of each group represented in the data base. These files are suitable for the transfer of data to commercially available programs for graphical and statistical analyses. The programming technique we describe could be extended to other model systems with standardized scoring for oral disease.
Animals↗
Medical Record Abstracting System/Information Delivery System (MRAS/IDS).
Explore the source record for details and available documents.
Abstracting and Indexing↗
A survey of the use of electronic scientific information resources among medical and dental students.
BACKGROUND: To evaluate medical and dental students' utilization of electronic information resources. METHODS: A web survey sent to 837 students (49.9% responded). RESULTS: Twenty-four per cent of medical students and nineteen per cent of dental students searched MEDLINE 2+ times/month for study purposes, and thiry-two per cent and twenty-four per cent respectively for research. Full-text articles were used 2+ times/month by thirty-three per cent of medical and ten per cent of dental students. Twelve per cent of respondents never utilized either MEDLINE or full-text articles. In multivariate models, the information-searching skills among students were significantly associated with use of MEDLINE and full-text articles. CONCLUSION: Use of electronic resources differs among students. Forty percent were non-users of full-text articles. Information-searching skills are correlated with the use of electronic resources, but the level of basic PC skills plays not a major role in using these resources. The student data shows that adequate training in information-searching skills will increase the use of electronic information resources.
Computer Literacy↗
Medical record linkage in health information systems by approximate string matching and clustering.
BACKGROUND: Multiplication of data sources within heterogeneous healthcare information systems always results in redundant information, split among multiple databases. Our objective is to detect exact and approximate duplicates within identity records, in order to attain a better quality of information and to permit cross-linkage among stand-alone and clustered databases. Furthermore, we need to assist human decision making, by computing a value reflecting identity proximity. METHODS: The proposed method is in three steps. The first step is to standardise and to index elementary identity fields, using blocking variables, in order to speed up information analysis. The second is to match similar pair records, relying on a global similarity value taken from the Porter-Jaro-Winkler algorithm. And the third is to create clusters of coherent related records, using graph drawing, agglomerative clustering methods and partitioning methods. RESULTS: The batch analysis of 300,000 "supposedly" distinct identities isolates 240,000 true unique records, 24,000 duplicates (clusters composed of 2 records) and 3,000 clusters whose size is greater than or equal to 3 records. CONCLUSION: Duplicate-free databases, used in conjunction with relevant indexes and similarity values, allow immediate (i.e. real-time) proximity detection when inserting a new identity.
Algorithms↗
Technical development of PubMed interact: an improved interface for MEDLINE/PubMed searches.
BACKGROUND: The project aims to create an alternative search interface for MEDLINE/PubMed that may provide assistance to the novice user and added convenience to the advanced user. An earlier version of the project was the 'Slider Interface for MEDLINE/PubMed searches' (SLIM) which provided JavaScript slider bars to control search parameters. In this new version, recent developments in Web-based technologies were implemented. These changes may prove to be even more valuable in enhancing user interactivity through client-side manipulation and management of results. RESULTS: PubMed Interact is a Web-based MEDLINE/PubMed search application built with HTML, JavaScript and PHP. It is implemented on a Windows Server 2003 with Apache 2.0.52, PHP 4.4.1 and MySQL 4.1.18. PHP scripts provide the backend engine that connects with E-Utilities and parses XML files. JavaScript manages client-side functionalities and converts Web pages into interactive platforms using dynamic HTML (DHTML), Document Object Model (DOM) tree manipulation and Ajax methods. With PubMed Interact, users can limit searches with JavaScript slider bars, preview result counts, delete citations from the list, display and add related articles and create relevance lists. Many interactive features occur at client-side, which allow instant feedback without reloading or refreshing the page resulting in a more efficient user experience. CONCLUSION: PubMed Interact is a highly interactive Web-based search application for MEDLINE/PubMed that explores recent trends in Web technologies like DOM tree manipulation and Ajax. It may become a valuable technical development for online medical search applications.
Consumer Behavior↗
Perspectives on the use of data mining in pharmaco-vigilance.
In the last 5 years, regulatory agencies and drug monitoring centres have been developing computerised data-mining methods to better identify reporting relationships in spontaneous reporting databases that could signal possible adverse drug reactions. At present, there are no guidelines or standards for the use of these methods in routine pharmaco-vigilance. In 2003, a group of statisticians, pharmaco-epidemiologists and pharmaco-vigilance professionals from the pharmaceutical industry and the US FDA formed the Pharmaceutical Research and Manufacturers of America-FDA Collaborative Working Group on Safety Evaluation Tools to review best practices for the use of these methods.In this paper, we provide an overview of: (i) the statistical and operational attributes of several currently used methods and their strengths and limitations; (ii) information about the characteristics of various postmarketing safety databases with which these tools can be deployed; (iii) analytical considerations for using safety data-mining methods and interpreting the results; and (iv) points to consider in integration of safety data mining with traditional pharmaco-vigilance methods. Perspectives from both the FDA and the industry are provided. Data mining is a potentially useful adjunct to traditional pharmaco-vigilance methods. The results of data mining should be viewed as hypothesis generating and should be evaluated in the context of other relevant data. The availability of a publicly accessible global safety database, which is updated on a frequent basis, would further enhance detection and communication about safety issues.
Adverse Drug Reaction Reporting Systems↗
Storage and utilization of images in otorhinolaryngology.
The amount of data in the field of otorhinolaryngology has rapidly increased, in proportion to the growing number of patients. Medical imaging has especially expanded and the percentage of image data in all information is also large. Because the space to preserve image films is increasing, it is very important to preserve them and make them easily available. Therefore, we have established a graphic filling system for storing endoscopic and radiographic images on VHS video tape and magnet-optical disk (MOD), using a personal computer. The MOD filing system is useful for storing a large amount of medical records. The user can simultaneously see the text data and the picture image on a display, and thus this system can be utilized as a database for both decision making and medical research.
Barium Sulfate↗
Building information systems to manage care and improve clinical quality.
Explore the source record for details and available documents.
Computer Communication Networks↗
Treatment of missing values with imputation for the analysis of otologic data.
Usefulness of imputation in the treatment of missing values in an otologic database was studied. Missing values were filled in with means (ME), regression (LR) and Expectation-Maximization (EM) imputation methods. A random imputation method (RA) provided baseline results. ME, LR and EM methods agreed on 41-42% of the imputed missing values. The level of agreement between these and RA method was 20-22%. Despite the moderate agreement, discriminant functions were similar and accurate (prediction accuracy 83-99%) for each diagnosis. A lot of data were missing in otoneurotologic tests which have less weight in the diagnosis of vertiginous patients. Consequently, the disagreement of the methods did not affect discriminant analysis. Inputation seems to be a useful method to treat missing data in this database, but future research requires more complete data and advanced imputation methods.
Data Collection↗
[Past, present and future of optical cards for medical use].
In the hospital, the chart is an important medical information record. However, it is not easy to refer to chart records. Although a computer is useful in referring to the chart, the most critical defect is the lack of exchangeability between hospitals. An optical card is a new medium for medical use. It has a large capacity for electronic storage, low price and high security. Therefore, the author considers this card a second medical chart. As another card, there is the IC card, which has some limitations in medical use. Although both systems are being examined experimentally, there is no actual practice in the medical field. The reason for this lack of wide use, it is thought that these systems are not yet supported by national health insurance.
Computer Communication Networks↗
Evaluating pharmacy benefit management information on the Internet: purpose, structure, technology, and content.
A wealth of health information is available on the Internet today. However, little is known about how to evaluate its quality and content. This exploratory analysis examined the Internet sites of 71 pharmacy benefit management firms that were operational in late 1999 by using components of several existing evaluation tools. Variables were used that incorporated interactive marketing strategy, technology features, and content. The principal findings suggest that health information on the Internet can and should be evaluated by users on dimensions such as purpose, structure, technology, and content. However, further work will be required to develop and test criteria.
Advertising↗
Structured data entry of clinical information for documentation and data collection.
Routine databases containing large amounts of clinical data represent a tremendous opportunity for the evaluation of health care practices and outcomes. However, data collected for administrative purposes has limitations in content, accuracy and completeness. Routine entry of clinical information directly into clinical information systems by care providers is one strategy to address this problem. We developed a structured data entry method, the Clinical Data Framework (CDF), which has been used to support the capture of clinical information by clinicians in the normal process of care delivery. A study of the CDF over a two month period showed that it improved the accuracy of completeness of data collection over a coding method which was based on selection of ICD-9-CM codes.
Data Collection↗